Generally, graphic overlay schemes allow overlay of multiple rectangular windows. Overlay schemes that support arbitrary shape objects are becoming increasingly necessary to support emerging shapes other than rectangles in, for example, graphics processing overlay such as video overlay.
Push-based deinterlacers may generally require a continuous feed of data from memory, which may place stringent quality of service (QoS) requirements on the memory controller and other related components. Sustaining a peak bandwidth requirement for such push-based deinterlacers may be increasingly difficult, where a line size may be about 1920 pixels or greater.
Further, typical push-based architectures work with two timing generators, one for the input and one for the output, to drive the display per the required output resolution/rate. These two timing generators are typically locked/synchronized so that video data is properly transferred across the video pipeline. Synchronization of the two timing generators may place significant demands on associated hardware and/or software.
Still further, a push-based deinterlacer may operate on the input clock rate for lack of back pressure to allow flow control. In such push-based deinterlacers, the input clock and the output clock may be adjusted to accommodate respective scaling ratios, which may require a complex timing scheme to tune the input and output clocks.
In typical graphic display applications, a plurality of images may be sent to the display engine and overlaid with each other for display. Portions of one image may block the display of another image. For example, a smaller subtitle image may block part of a video image. The portions of the video image behind the subtitle image may not be displayed or seen. Thus, the bandwidth for transferring the image data for the region of the video image that is hidden from view by the subtitle image may be wasted.